Operation of diagnostic devices involving microchannels and electrodes

ABSTRACT

An assembly is provided for interfacing with a microfluidic chip having at least one microscopic channel configured to receive a liquid sample for analysis. The assembly includes a chip carrier, an electronics module, an optical module, and a mechanical module. The chip carrier includes a base and a cover defining a cavity to receive the microfluidic chip. The electronics module includes a signal generator which applies at least one electrokinetic signal electrode(s) of the chip. The optical module includes an excitation radiation source which causes excitation radiation to impinge on the sample, and an emission radiation detector which detects radiation emitted from the sample. The mechanical module includes a chip-carrier receiving structure, relatable with respect to the optical module for focus and at least one degree of translational freedom.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.15/199,529 filed Jun. 30, 2016, the complete disclosure of which isexpressly incorporated herein by reference in its entirety for allpurposes, which in turn claims the benefit of U.S. ProvisionalApplication 62/271,732 filed Dec. 28, 2015, the complete disclosure ofwhich is also expressly incorporated by reference herein in its entiretyfor all purposes.

STATEMENT OF GOVERNMENT RIGHTS

Not Applicable.

FIELD OF THE INVENTION

The present invention relates to the electrical, electronic and computerarts, and, more particularly, to healthcare and/or environmentalsolutions and the like.

BACKGROUND OF THE INVENTION

There has been a rapid increase in microfluidics-based Point-of-Care(PoC) devices, with potential as miniaturized laboratory platforms.Microfluidic devices typically have one or several microchannels. Byincluding electrodes in microchannels, it is possible to applyelectrical fields in a volume element of a liquid. This enableselectrochemical detection of analytes, electroosmotic flow,dielectrophoresis (DEP) of particles or cells in microchannels,electrophoretic separation of particles and molecules, local heating,electrochemiluminescence, etc.

DEP is particularly interesting because it can generate a force bypolarizing a suspended dielectric particle within a non-homogeneouselectric field. Particle or cell manipulation via DEP therefore requirescreating an electric field gradient, which is commonly done using planarmetallic electrodes integrated or in close proximity to the microfluidicchannel. Such electrode arrays are typically powered by applyingalternating (AC) electric fields in the range of dozens of kHz up tohundreds of MHz. For this, the microfluidic device also needs to havetwo or more contact areas for powering the electrodes using a wavegenerator.

Fluorescence-based assays are widely used for detecting analytes.Fluorescence markers require optical detection with very sharp filtersfor the efficient separation between excitation light and fluorescentemission (usually, the fluorescence dyes have relatively small Stokesshift, of about 50 nm).

There are two known solutions:

-   -   1) Fluorescence microscopes +electronic laboratory bench signal        generator: Very expensive and bulky setup equipment, not        suitable for low cost point-of-care (PoC) applications (>$50 k)        and also demands a laboratory infrastructure, but provides a        high quality fluorescence analysis, using high quality light        source, high quality filters and beam splitters, and can be        equipped with very high sensitivity and low noise cameras with        Peltier cooling, which obtains super high resolution        fluorescence images and videos.    -   2) Lower cost and portable optical measurement devices or        readers with miniaturized fluorescence optical detection system        (LED illumination, focusing lens, dichroic mirror and        photodetector), but these solutions are appropriate only for        cellulose or paper strips (i.e. lateral low assays) and do not        have embedded signal generators for DEP signal generation.        Although cheaper than a

Fluorescence Microscope, will still cost several thousands of dollars(typically $8K-10K).

SUMMARY OF THE INVENTION

Principles of the invention provide techniques for diagnostic devicesinvolving microchannels and electrodes and/or their operation. In oneaspect, an exemplary assembly is provided for interfacing with amicrofluidic chip having at least one microscopic channel configured toreceive a liquid sample for analysis, at least one electrode embedded inthe channel, and at least one chip contact coupled to the at least oneembedded electrode. The assembly includes a chip carrier, in turnincluding a base; a cover, cooperatively defining, with the base, acavity configured and dimensioned to receive the microfluidic chip; andat least one chip carrier contact to engage the at least one chipcontact. The cover is attachable to the base, to secure the microfluidicchip in the cavity of the base. The cover has an aperture to permit themicroscopic channel of the microfluidic chip to receive the sample foranalysis and to permit passage of excitation and emission radiation. Theassembly also includes an electronics module, in turn including at leastone electronics module contact that engages the at least one chipcarrier contact; and a signal generator, coupled to the at least oneelectronics module contact, which applies at least one electrokineticsignal to the at least one embedded electrode. The assembly even furtherincludes an optical module, in turn including an excitation radiationsource which causes excitation radiation to impinge on the samplethrough the aperture; and an emission radiation detector which detectsradiation emitted from the sample through the aperture. Still further,the assembly includes a mechanical module including a chip-carrierreceiving structure, relatable with respect to the optical module forfocus and at least one degree of translational freedom. The mechanicalmodule is electrically coupled to the electronics module. The focus andthe at least one degree of translational freedom are controlled by theelectronics module via the electrical coupling.

In another aspect, an exemplary method is provided for carrying out atest on a microfluidic chip having at least one microscopic channelconfigured to receive a liquid sample for analysis, at least oneanalytic electrode embedded in the channel, a plurality ofliquid-presence-sensing electrodes embedded in the channel, and aplurality of chip contacts coupled to the at least one analyticelectrode and the plurality of liquid-presence-sensing electrodes. Themethod includes detecting loading of the liquid sample, on a first suchmicrofluidic chip, based on an impedance change at a first one of theliquid-presence-sensing electrodes; responsive to detecting the loading,on the first such microfluidic chip, starting a timer; and, responsiveto an impedance change at at least another one of the embeddedliquid-presence-sensing electrodes, on the first such microfluidic chip,when the timer has advanced past a first threshold but has not advancedpast a second threshold, commencing application of electrokineticsignals to the at least one embedded analytic electrode.

As used herein, “facilitating” an action includes performing the action,making the action easier, helping to carry the action out, or causingthe action to be performed. Thus, by way of example and not limitation,instructions executing on one processor might facilitate an actioncarried out by instructions executing on a remote processor, by sendingappropriate data or commands to cause or aid the action to be performed.For the avoidance of doubt, where an actor facilitates an action byother than performing the action, the action is nevertheless performedby some entity or combination of entities.

One or more embodiments of methods and/or assemblies in accordance withaspects of the invention can be implemented together with computingdevices such as a “smart” phone or similar mobile device, and/or incommunication with one or more cloud computing nodes in a cloudcomputing environment. At least some such implementations can make useof suitable software (e.g., for test control and/or analysis of testresults) embodied as computer program product including a computerreadable storage medium with computer usable program code for performingpertinent method steps based, e.g., on sensor input. A cloud computingnode and/or “smart” phone or similar mobile device will include amemory, and at least one processor that is coupled to the memory andoperative to perform pertinent method steps. Yet further, in anotheraspect, one or more embodiments of the invention or elements thereof canbe implemented in the form of means for carrying out one or more of themethod steps described herein; the means include those disclosed herein.Means for some aspects can include, for example, (i) hardware module(s),(ii) software module(s) stored in a computer readable storage medium (ormultiple such media) and implemented on a hardware processor, or (iii) acombination of (i) and (ii); any of (i)-(iii) implement specifictechniques.

Techniques of the present invention can provide substantial beneficialtechnical effects. For example, one or more embodiments solve theproblem of obtaining a portable fluorescence reader that includeselectronics suitable to generate and excite the electrodes inmicrochannels, with electrical signals suitable to execute theaforementioned phenomena. One or more embodiments of the presentinvention provide a portable and compact solution integrating theoptical, electrical, mechanical and computational elements required fordielectrophoretic manipulation of particles and fluorescent orcolorimetric analyte detection. Furthermore, one or more embodimentsprovide user friendly and user independent operation, which can becontrolled remotely, at low cost and low energy consumption.

These and other features and advantages of the present invention willbecome apparent from the following detailed description of illustrativeembodiments thereof, which is to be read in connection with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 show block diagrams of an exemplary apparatus, inaccordance with an aspect of the invention;

FIG. 3 shows a flow chart of an exemplary method, in accordance with anaspect of the invention;

FIG. 4 shows several views of an exemplary chip holder with foldingframe design for microfluidic chips, in accordance with an aspect of theinvention;

FIG. 5 shows a first exemplary detailed form of an exemplary chip holderwith folding frame design for microfluidic chips, wherein the frame iscombined with an optical reader and electronic module, in accordancewith an aspect of the invention;

FIG. 6 shows a flow chart of an exemplary detailed method useful withrespect to the frame of FIG. 5, in accordance with an aspect of theinvention;

FIG. 7 shows a second exemplary detailed form of an exemplary chipholder with folding frame design for microfluidic chips, wherein theoptical reader and electronic module are two independent units, inaccordance with an aspect of the invention;

FIG. 8 shows an exemplary series of workflow steps and protocol, usefulin connection with the frame of FIG. 7, in accordance with an aspect ofthe invention;

FIG. 9 shows a third exemplary detailed form of an exemplary chip holderwith folding frame design for microfluidic chips, wherein the opticalreader and electronic module are integrated to the folding frame, inaccordance with an aspect of the invention;

FIG. 10 shows a circuit diagram of an amplification stage suitable forDEP signal generation, in accordance with an aspect of the invention;

FIG. 11 shows an exploded view of the first embodiment of the system, inaccordance with an aspect of the invention;

FIGS. 12-15 show various views of a second embodiment of a system, inaccordance with an aspect of the invention;

FIGS. 16-26 show various views of a third embodiment of a system, inaccordance with an aspect of the invention;

FIGS. 27-30 show various views of a fourth embodiment of a system, inaccordance with an aspect of the invention;

FIG. 31 shows a flow chart associated with the fourth embodiment of thesystem, in accordance with an aspect of the invention;

FIGS. 32 and 33 show a plan view and circuit diagram associated withtesting aspects of the fourth embodiment of the system, in accordancewith an aspect of the invention;

FIG. 34 shows a graph of capacitance versus time from the testingaspects of FIGS. 32 and 33, in accordance with an aspect of theinvention;

FIG. 35 shows a circuit diagram of a DEP cartridge of the third andfourth embodiment of the system;

FIGS. 36-39 show various views of a fifth embodiment of a system, inaccordance with an aspect of the invention;

FIG. 40 is a block diagram of a “smart” phone or tablet computer usefulin one or more embodiments of the invention;

FIG. 41 depicts a cloud computing node according to an embodiment of thepresent invention;

FIG. 42 depicts a cloud computing environment according to an embodimentof the present invention; and

FIG. 43 depicts abstraction model layers according to an embodiment ofthe present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

One or more embodiments advantageously provide a system that serves tocarry out diagnostic operations on microfluidic based chips or devicesinvolving microscopic channels with embedded metallic electrodes. Thesedevices guide the flow of fluids in the microscale, but they alsoincorporate two key elements:

-   -   Embedded metallic electrodes creating an electric field in the        microchannel capable of manipulating the fluid and suspended        microparticles (in particular, metallic electrodes deposited on        areas of the microchannel walls capable of creating an electric        field distribution inside the fluid flowing along the        microchannel with useful effects over the fluid and suspended        microparticles that manifest themselves only in the microscopic        scale);    -   A diagnostic based on the detection of fluorescent emission from        the target molecules (typically, from fluorescence labels        attached to the target molecules).

Fluorescent detection often requires expensive and bulky fluorescentmicroscopes, while additional electrical equipment is needed to powerthe electrodes, making the entire setup expensive, cumbersome and hardlyportable, relying on laboratory infrastructure to be able to operateproperly.

One or more embodiments provide a portable and significantly moreaffordable apparatus, including a microfluidic chip carrier andperipherals with electrical, optical, and wireless addressingcapabilities, including four main modules:

-   -   A mechanical module to facilitate chip manipulation    -   An electronics module to power and control the electrodes        operation    -   An optical detection module    -   A signal processing and communication module.

In one or more embodiments, the modules are operated according to thefollowing sequence:

-   -   Chip loading, alignment and sample input    -   Electric signal control to drive analysis    -   Optical detection    -   Result processing and communications of final diagnostic.

With regard to microfluidic chips in the context of portable sensing,microfluidic chips can be powerful devices for performing (bio)analysis:many types of reagents can be integrated to microfluidic devices and thehigh precision with which liquids and samples can be moved throughoutmicrofluidic devices, combined with very small liquid volumes, enablefast, precise and sensitive assays to be performed. The small formfactor of microfluidic chips also make them well suited for portablesensing applications (e.g. point-of-care testing, environmentalmonitoring, diagnostics in poor settings areas, etc.). However,depending on the sensing mechanism, microfluidics chip layout, and assayprinciples, peripherals may be needed. Interfacing peripherals withchips is not a trivial problem because:

-   -   1. Chips and peripherals should all together support        portability.    -   2. The chips should be easily and reliably interfaced/removed        with/from peripherals by non-technical experts.    -   3. Operating the chips and peripherals with samples should be        safe, with a suitable operation procedure to avoid        cross-contamination between different samples.    -   4. The chips and peripherals should allow using capillary-driven        flow (this requires vents and a loading pad for placing a        sample, and provides relief from using bulky, expensive active        pumping techniques).    -   5. It is also advantageous to have electrical connections to the        chip for e.g. monitoring and flow control, detecting        electroactive species, or concentrating particles via        dielectrophoresis.    -   6. It is also advantageous to have a well-defined optical path        to some areas of the chip for optical monitoring and reading        optical signals, such as fluorescence or colorimetric signals.    -   7. It is also advantageous to have the chip connected to a        mobile computing device to provide access to the Internet and/or        to use the mobile computing device for local data processing and        aggregation.    -   8. Finally, chips should be small to minimize manufacturing        costs; in particular, when Si wafers and microtechnology are        used for producing chips. In addition, small chips would require        small sample volumes, which provide ease in analysis and faster        chemical/immunoassay reactions, necessary to obtain quick        results.

We have found that it is appropriate to take steps to minimize corrosionand contamination. The alternating current (AC) fields needed fordielectrophoresis put strong limitations on the metals that can be used.Pd, Pt, or Au are typically used for these reasons; however, they arevery expensive and need to be patterned as thin layers. This createssignificant wear/contact challenges. We have found that it is desirableto avoid relying on sliding sockets only, where practicable. Chips aretypically small (1 to 2 cm²) to minimize fabrication cost. Due careshould be taken when using small chips to manage any safety issues withoverflow of sample (e.g. blood for infectious diseases diagnostics). Theliquid loading pad, detection area and electrical contacts are typicallylocated on the same side of the chip. Additionally, we have found thatthe loading pad, detection area, and electrical contacts shouldpreferably not be placed too close to each other, to minimize risk ofsample overflow and electrical shorts or surface contamination. Giventhe teachings herein, including these guidelines, the skilled artisanwill be able to appropriately locate these features for particularapplications of embodiments of the invention.

Capillary filling needs vents for displacing air during filling of thechip. Liquids should not leak out of the chip or through vents forsafety and contamination reasons. Electrical contacts should not occupytoo much space on the chip, while yet being present in sufficientnumbers for proper chip operation. We had poor experience with directlyinserting chips to a socket with spring loaded contacts because thetranslational (x, y, z) positioning and/or alignment of the chip withrespect to an optical reader was not reproducible. In particular, chipstended to be tilted and partially out of focus, perhaps because thespring loaded electrical contacts were pressing the laterally insertedchips differently each time.

In some applications, microfluidic chips present certain areas withinthe microchannel containing electrodes, which can be long and parallel,short, in the form or arrays or other shapes, such that they can be usedfor trapping various populations of beads. Furthermore in this regard,note that some versions of the microfluidics chips include bead sortingcapabilities. For example, such chips are capable of sorting beads withdifferent diameter or sorting beads that are made of differentmaterials. Positioning the optical system on a specific area requiredusing a large and expensive fluorescence microscope stage. Readingoptical signals on the chips may require various magnifications or lightwavelengths. Therefore, the chip should not have physical structures(e.g. loading pad) that might collide with optical lenses or components.A 1 mm up to 1 cm optical working distance is desired.

Stray light might be detected and lead to false positives. Electricalcross-talk (interference) for high frequency signals (e.g. DEP) shouldbe avoided.

Heretofore, problems have arisen in the electrical connection ofmicrofluidic devices and a fluorescence reader. Fluorescence microscopesare expensive and bulky. They provide proper excitation light at theabsorption wavelength and high quality filters for separating the muchweaker fluorescent radiation from the excitation light. They can beequipped with very high sensitivity and low noise cameras with Peltiercooling, which obtains super high resolution fluorescence images andvideos. They are also very expensive equipment not suitable for low costPoC applications (>$50 k). They are used in connection with anelectronic laboratory bench signal generator, and require a laboratoryinfrastructure.

Lower cost and portable optical measurement devices or readers with aminiaturized fluorescence optical detection system (LED illumination,focusing lens, dichroic mirror and photodetector) have also been usedheretofore, but these solutions are appropriate only for cellulose orpaper strips (i.e. lateral low assays (qualitative)). Although cheaperthan a Fluorescence Microscope, these systems still cost severalthousands of dollars (typically ˜$8K-10K). Current systems do notinclude the electronics necessary to power the electrodes embedded inthe microchannels.

Microfluidic chips for fluorescence-based assays not only need afluorescence optical setup but can also require an actuation and/orexcitation source for the electrodes (e.g. for DEP). Using contact padson a microfluidic device, with an electrical socket and peripheral wavesignal generator is cumbersome (cables, microscopes, oscilloscopes andvarious peripherals are needed). As alluded to above, stray light,vibrations and motions of the microfluidic device can negatively affectfluorescence signal measurements.

One or more embodiments consider the following design constraints andrequirements, due to the detection methodology used, and the smalldimensions and materials used on the microfluidics chip. Otherembodiments could take a different approach. Fluorescence analysis(excitation and fluorescence light) is executed from the top of thechip, because it is made of silicon (which is opaque). Only the chipcover is transparent and the sample is therefore deposited from the top.The platform aligns carefully to the laser spot with respect to the DEParea (on the x, y and z directions), so that the fluorescence signal iscorrectly obtained and a correct analysis is executed. For optimalfluorescence signal (i.e.: maximize DEP area filled with microbeads),DEP signal amplitude and time multiplexing (turning on/off DEP signal)is also an appropriate method. Time multiplexing depends on the beadsize and flow speed (which is determined by the microfluidics chipcharacteristics, such as height and width of the microchannels). One ormore DEP signal generators, which can be individually adjusted inamplitude and frequency, are used in different electrode pairs, in whichthe function can be sorting (e.g.: isolate a certain bead with aspecific diameter or with certain composition) or trapping to detect thefluorescence from the beads. Again, electric contacts should be as faras possible from the loading pad, to avoid biohazard contamination ofthe mechanical interface between the microfluidics chip and the socketand/or mechanical chip handler. Complete darkness is required, due tointerference that room illumination and/or sunlight causes influorescence detection. Hence, a black container is used in one or moreembodiments to eliminate external light and provide separation betweenoptical and electrical modules to avoid interference.

For correct fluorescence analysis, the microfluidics chip should befixed in the proper position; one or more embodiments employ a chipalignment structure made of a suitable material (plastic is onenon-limiting example), with suitable format, to keep the chip in thesame position, as compared with the electrode socket. The fluorescencereader should be convenient for use by the end user, so that there areessentially three steps to execute an analysis: insert the microfluidicschip in the socket; pipette the sample; and start fluorescence analysis.

FIGS. 1 and 2 show block diagrams of an exemplary apparatus, inaccordance with an aspect of the invention. In one or more embodiments,a portable apparatus includes mechanical and electronic componentsnecessary to power electrodes that are integrated to a microfluidicdevice, a fluorescence detection module, and a signal processing andcommunications module. In a non-limiting exemplary embodiment, themechanical module 102 includes mechanical elements to manipulate thechip as well as other sample preparation and/or post-processing elementssuch as for rinsing or mixing with other fluids, and the like. Forexample, mechanical module 102 can include chip holder platform 104,fluid vials and holders 106, socket 197 and alignment structures 108.

In the non-limiting exemplary embodiment, electro-kinetic (DEP) controlelectronics module 110 controls the electrode excitation operation andincludes AC signal generator 112, electronics 114 for the control of themechanical parts in charge of alignment between the microfluidics chipand optical components 122, and a power source and/or battery controlcircuit such as 116.

Furthermore, in the non-limiting exemplary embodiment, in detection oroptical module 118, the interface to the biological signal can beoptical (fluorescent or colorimetric) or can be based on other physicalproperties (impedance, magnetic, etc.). Module 118 also includes lightsource 120 and optical elements (lens, filters) 122, and aphotodetector, image sensor, and/or camera 124, which can be modified,depending on the detection method.

Finally, in the non-limiting exemplary embodiment, signal processing andcommunications module 126 includes a processor unit 128, memory 130,display and/or other user interface 132, and communications interface134 (which can be wired and/or wireless). In some instances, theprocessor and memory are provided as part of a microcontroller, as seenin FIG. 1.

Continuing to refer to FIGS. 1 and 2, and referring now also to the flowchart of FIG. 3, operation of the system once the chip is inserted(e.g., chip 199 is inserted into socket 197) is made autonomous byfollowing several pre-determined steps. The user, through a userinterface 132, can adjust the reader device to properly execute thedesired analysis. The steps depicted in FIG. 3, in the non-limitingexample shown, are depicted in chronological order starting with thefirst and proceeding to the last. Other embodiments can use a differentorder of the referred steps, and/or add or omit some steps, ifappropriate. Step 202, carried out by mechanical module 102, includeschip loading. Optionally, in step 204, mechanical module 102 undertakeschip platform adjustments, which can follow a fixed sequence, or ifvisual of the chip is available, can include real-time adjustments tooptimize the fluorescence signal. Step 204 can also include focaladjustment and/or in-plane alignment. Step 206, carried out with the aidof mechanical module 102, includes sample input and/or deposition, whichis executed by the user.

In optional step 208, an experiment clock can be initiated by signalprocessing module 126 in order to follow a pre-determined and pre-timedsequence that allows the sample to fill up the microfluidics channeluntil it reaches the DEP signal and fluorescent measurement region. Instep 210, signal processing module 126 starts the DEP signal generator112. In step 212, optics module 118 executes fluorescence measurement.In step 216, the fluorescence measurement is processed by signalprocessing module 126. In step 218, optics module 118 finishes thefluorescence measurements. In step 220, the signal processing module 126stops the AC signal generator 112.

In step 222, signal processing module 126 processes the fluorescentdata; in step 224, module 126 displays the results via human interface132; and in step 226, module 126 provides the results to externaldevices (e.g.: cloud server 12 discussed below) via communicationsinterface 134. Not every embodiment will necessarily include both step224 and 226.

While an experimental clock can be initiated in order to follow apre-determined and pre-timed sequence of DEP signal and fluorescentmeasurement, alternatively, the signal sequence control can use feedbackfrom the experiment (optical, electrical, magnetic or otherwise).Similarly, the detection signal can be measured at a fixed window oftime and/or number of measurements after the experiment has started, asdefined based on prior experience, or the signal can be measuredcontinuously until an indication that saturation has been reached.Finally, results can be displayed and/or transferred wired and/orwirelessly to a database server or other suitable destination, forfurther processing.

FIG. 4 shows several views of an exemplary folding frame formicrofluidic chips, in accordance with an aspect of the invention (e.g.,for use in the mechanical module 102). In particular, view 228 is a sideview, view 230 is a top view, and view 232 depicts chip insertion. Theexemplary folding frame provides mechanical, electrical, optical, and,on some embodiments, wireless addressing capabilities with variousperipherals. Note out-of-plane spring-loaded electrical contacts 234(e.g. Pogo-pin), which provides a greater number of contacts in a smallchip area; cavity 236 to place and align the chip 238; and spring-loadedcover 240 with lock and unlock mechanism 242. Cover 240 presses the chipfrom the top for mechanical fixity, electrical contact purposes, andalso to maintain chip flatness for better focusing. In some cases, thebottom side 246 of the cover 240 can have a hydrophobic cushion layerfor compliancy and to prevent liquid leakage to the contacts 234. Alsoprovided is an opening 244 in the cover 240 to allow liquid loading(seen at 250) and optical detection. Optionally, a mechanism can beadded to “lever up” the chip for easier removal when measurement isdone. A flexible cable 248 connects with the contacts 234. Note alsohinges 252.

In one or more embodiments, the height h should be carefully controlledfor optical read-out at potentially high magnification.

One or more embodiments are advantageously low cost, easy to operate,and can be interfaced with many peripherals.

FIG. 5 shows a first exemplary detailed form of an exemplary foldingframe for microfluidic chips, wherein the folding frame is combined withan optical reader module 118 and electronic module 110 using a traymechanism, in accordance with an aspect of the invention, obtaining afully functional detection unit. Advantages include ease of chiphandling, compactness, portability, and stand-alone capability.Furthermore, the tray can be moved for scanning, as seen at 254, whichsimplifies the optics. Yet further, the frame can be replaced fordifferent chip dimensions, layout and/or versions, which results in amore flexible design. In one or more embodiments of this type, the chipis electrically connected and/or powered early on (for example, evenbefore the sample is loaded), such that the flow can be monitored rightfrom the beginning of the process. The electronics module 110 detects ifa chip is present and also that the electrical contacts are functioningproperly (e.g., via capacitance measurements).

FIG. 6 shows a flow chart of an exemplary detailed method useful withrespect to the frame of FIG. 5, in accordance with an aspect of theinvention. Steps 256, 258, 260, 262, and 264 pertain to the microfluidicchip frame per se. In step 256, pull out the tray, to provide access tochip cavity 236. In step 258, activate the chip detection and flowmonitoring electronics. In step 260, load the chip into cavity 236. Instep 262, pipette the liquid into microfluidics chip loading pad. Instep 264, insert the frame into the tray.

Steps 266, 268, 270, 272, 274, 276, 278, 280, and 282 pertain to theelectrical, optical, signal processing, and wireless communicationunits. In step 266, monitor the liquid flow, to track when the liquidsample meniscus arrives and fills up the DEP area. In step 268, startthe DEP signal and bead trapping. In step 270, adjust focus. In step272, start the fluorescence measurements. In step 274, scan themicrofluidics chip with the optics. In step 276, process the data. Instep 278, display and/or otherwise communicate the results. In step 280,complete the fluorescence measurements. In step 282, stop the DEPsignal.

Steps 284, 286, and 288 pertain to the microfluidic chip frame per se.In step 284, pull out the tray to have access to the used chip. In step286, dispose of the chip, in compliance with any applicable rules,regulations, or procedures pertaining to biological/medical samples orthe like. In step 288, insert the frame into the tray.

FIG. 7 shows a second exemplary detailed form of an exemplary foldingframe for microfluidic chips, wherein the optical reader and electronicmodule are two independent units, in accordance with an aspect of theinvention. In particular, the optical unit 118 is separate from theframe, as in FIG. 5, but the frame includes electronics module 110. Inthis way, tests can be run in parallel with only one optical readerneeded to measure final results. The tighter integration with electricalconnections provides less parasitics, improving measurement precision,and the approach is compatible with “electrical” detection techniques(e.g. impedimetric and/or electrochemical assays). Additional contacts290 are provided for electrical communication between the optical readerand electronic module.

FIG. 8 shows an exemplary series of workflow steps and protocol, usefulin connection with the frame of FIG. 7, in accordance with an aspect ofthe invention. In a first step 301, insert the chip 238 into the frame.In a second step 302, the chip is detected and a chip and/or sample ID(identifier) is/are assigned. In a third step 303, the sample isdetected and liquid flow monitoring is activated. In a fourth step 304,the DEP is activated when the liquid arrives at the DEP region and theliquid flow is monitored. In a fifth step 305, the combined frame andelectronics module are ready to be inserted into the optics module 118for detection. In a sixth step 306, communication with the reader isestablished, auto focus is carried out, and scanning and detection arecommenced. In a seventh step 307, the results are displayed and/or sentelsewhere. In an eight step 308, the chip 238 is disposed of.

FIG. 9 shows a third exemplary detailed form of an exemplary foldingframe for microfluidic chips, wherein the optical reader and electronicmodule are both integrated into the frame, in accordance with an aspectof the invention. View 999 is a side view with the frame open to receivethe chip 238, while view 997 is a side view with the chip inserted.Elements essentially the same as those discussed above have received thesame reference character; while, as will be appreciated by the skilledartisan, elements in this alternative embodiment which are generallyanalogous to those discussed above have received the same referencecharacter incremented by seven hundred. The spring-loaded cover 940 hasa lock and unlock mechanism 942. In some cases, the bottom side 946, thecover 940, and the cavity 236 can have a hydrophobic cushion layer forcompliancy and to prevent liquid leakage to the contacts 234. Alsoprovided is an opening 944 in the cover 940 to allow sample loading(seen at 250). A flexible cable 948 connects with the contacts 234. Thetop and bottom sides are connected by hinges 952.

The hinged cover 940 includes light source and detector 993, a display995 for visual feedback, filters 992, and optics with beam scanning andfocusing 991, while the bottom portion of the frame (not separatelynumbered) includes the electronics module 110, wireless communicationunit, and battery. In particular, electronics module 110 can includemain board 989, battery 987, and wireless unit 985. Furthermore, theoptical unit 118 can include, for example, a mechanical unit 983 (e.g.,including a stepper motor to impart linear motion), a mirror 981 andlens 979, and a microcontroller with USB interface. Focusing is as shownat 977 (up and down as compared to sample when assembly is closed) whilebeam scanning is as shown at 975 (back and forth as compared to samplewhen assembly is closed, as well as into and out of the plane of thepaper, so as to scan a planar region). In a non-limiting example, thebeam scanning range of motion can be 1-2 cm. Furthermore, in anon-limiting example, the optical unit can have dimensions of 50 mm wideby 80 mm long by 50 mm high, an optical working distance of 1-10 mm, anda detection area/resolution of 1 μm² (single bead detection) and 0.01-10mm² (integrated area).

Exemplary advantages of the embodiment of FIG. 9 include compactness,portability, stand-alone capability, and ease of use. Furthermore,overspill of the sample is easier to clean, inasmuch as the loading padis left out of the closing part of the frame.

In a non-limiting example, the microfluidic chip can have dimensions ofabout 10 mm width, 30 mm length, and 2 mm thickness, and can handle aliquid volume of from 1-10 μL. Furthermore, the mobile electrical unitcan have, for example, dimensions of 30 mm width, 80 mm length, and 20mm height. The DEP signal can, for example, range from 5-25 Vpp at afrequency of 100 kHz-3 MHz. Flow monitoring can be carried out at, forexample, 1-5V at frequencies from DC up to 100 kHz.

In a non-limiting example, the microfluidic chip 238 includes electricalcontacts at 967, a detection area at 969, a plastic housing 971, aloading pad 973, and a chip substrate 965 with microfluidic channels andmicroelectrodes.

First exemplary embodiment: FIG. 10 shows a circuit diagram of anamplification stage suitable for use in a first exemplary embodiment,while FIG. 11 shows an exploded view of the first exemplary embodiment.In this first exemplary embodiment, the modules include optical anddetection module 118. This can be implemented, for example, as acommercial fluorescence measurement module by from Qiagen N.V. ofHilden, Germany, or other supplier, including light sources (e.g., LED),lens(es), filters and a photo detector. A custom made version can alsobe applied in this case such as in the example of FIG. 5. Optical moduleoutput is in the form of a single voltage value proportional to theintegrated fluorescence intensity over the photo detector measurementarea. Mechanical module 102 handles chip-reader interface needs toaccommodate the need for complete darkness during measurement—thus, themicrofluidic chip is entirely inside the reader in this example. Apush-to-click mechanism easily secures the chip and provides alignmentwith the DEP area and optical module 118 (for instance, using thewell-known ExpressCard/34 interface slot as an interface solution). In anon-limiting example, the box 1101 is 20.5 cm wide×19 cm deep×10.5 cmhigh. An internal plastic division 1103 separates the prototype board1105 from the chip and optical module. In this non-limiting example, thechip drawer 1107 is 3.4 cm wide×0.3 cm high×6.0 cm deep. The distance Xfrom the microfluidics chip to the optical module is 3 mm, the internalplastic division 1103 is 3.5 cm from the case bottom, and the internalplastic division 1103 measures 19 cm wide×15.5 cm deep.

In a non-limiting example, the Electronics and Data (signal) processingmodules 110, 126, 1105 are integrated into a single unit and employ aCY8CKIT-001 PSoC Development Kit common development platform availablefrom Cypress Semiconductor Corporation, San Jose, Calif., USA, as rapidprototype of signal generation/control/logic analysis of thefluorescence reader. This is combined with the amplification stagedescribed in FIG. 10. Components include an AC signal generator(providing sinusoidal wave, square wave, and the like) with variablefrequency (by varying the signal generator inside the microcontroller orvarying the oscillator frequency) to be applied to electrodes in themicrofluidic chip in order to generate and control the DEP forces atvarious locations along the microchannel. Reader prototype controlhandles set-up, fluorescence analysis options, and the like.Fluorescence signal processing and display in LCD is also provided. Thecommunication module can be wired (e.g. serial standards, such as I²C,SPI and UART) or wireless (e.g. such as Bluetooth). The interfacebetween the microfluidic chip and electronics can be provided, forexample, through a discrete socket component.

Referring to FIG. 10, a suitable amplification stage 1004 executesvariable amplitude (by varying the G gain in the amplification stage) tobe applied to the electrodes in the microfluidic chip in order togenerate and control the DEP forces at various locations along themicrochannel. This stage executes the electrode configuration, so eachelectrode can be changed individually (signal output routing stage).Signal processing stage 126 includes communications interface 134 (wiredand/or wireless) with a microcontroller 128, 130 as discussed above andsignal generator 1002. Signal generator 1002 generates 1 through ndifferent signal waveforms. These are supplied to the amplificationstage 1004 which includes n individual amplification stages with gainsG1 through Gn, in turn providing n amplified output waveforms to thesignal output routing stage 1006. Signal output routing stage 1006includes m multiplexers 1 through m with outputs connected to the melectrodes. Each multiplexer has as its selectable inputs ground, noconnection and DEP output 1 to DEP output n. Details are shown at thebottom of the figure. The n individual amplification stages G1 throughGn each include a capacitor 1010-1, 1010-n coupled to the negative inputof an operational amplifier (op amp) 1012-1, 1012-n which has itspositive input grounded; a digital potentiometer 1014-1, 1014-nproviding feedback from the output of the op amp back to the negativeinput, and a buffer 1016-1, 1016-n at the op amp output. Thecorresponding outputs are DEP output 1 through DEP output n.

These outputs can be selectively applied to the appropriate electrodesvia the signal output routing stage 1006. Please note that themultiplexers 1008-1 thru m in the upper part of the figure are ageneralized depiction, while the multiplexers 1018-1 thru n in the lowerpart of the figure represent a particular exemplary implementation usedin the first exemplary embodiment. Thus, in a general case, there can befrom one up to n DEP signal generators, with one up to m electrodes. Inthe specific first exemplary embodiment, there are only two DEP signalgenerators; thus, at the top, each multiplexer has inputs 1, n, ground,no connection, while at the bottom each multiplexer has inputs 1, 2,ground, no connection.

DC/DC converter stage 1020 provides the symmetric voltage sourcenecessary for the DEP amplification stage 1004. In this example, it has+12 V as input and ground, and provides as output +/−15 V.

Second exemplary embodiment: FIGS. 12-15 show various views of a secondexemplary embodiment of a system, in accordance with an aspect of theinvention. In the second embodiment, the commercial optical module isreplaced by a customized setup including a CMOS or CCD image sensor foroptical detection (fluorescence or colorimetric) with spatial resolutionfor more advanced image processing of the detection area and morequantitative analysis; a light source; various lenses; and filters. Inone configuration, the device is customized to be used with opaquemicrofluidic chips such as those manufactured on silicon substrate. Suchconfiguration implies illumination and detection from above the chip anda minimum distance between the chip and the image sensor. Themagnification can be customized for the application (by way of exampleand not limitation, 100-120 x). Moving the stage in three dimensions forfocus and in-plane alignment is also provided, for better imageacquisition, in at least some instances. Data can be sent to a mobiledevice (e.g., smart phone, tablet) or computer using a wirelessinterface (e.g.: Bluetooth, NFC, Wi-Fi), for visualization and analysis.

Several types of custom optical module can be employed; for example, onewith analog interface and fixed beam, as in FIGS. 13 and 15, and anotherwith digital interface and beam scanning, as in FIG. 12. In theembodiment of FIG. 12, note stepper motor 1201 providing linear motionsymbolized by arrows 1205 (e.g., 1-2 cm of beam scanning); mirror andlens housing 1203; light source 1209 (LED or laser); optionalcollimating lens 1211; mirror 1213; excitation filter 1215; dichroicmirror 1217; emission filter 1219; optional lens rack 1221; andphotodiode or camera 1223. Note also microcontroller and USB interface1225. The analog interface and fixed beam version shown in FIGS. 13 and15 is generally similar, except its mirror and lens housing 1207 isfixed and it omits interface 1225. As seen in FIG. 15, housing 1207includes mirror 1227 and lens 1229. Housing 1203 can house a similarlens and mirror (not shown to avoid clutter). FIG. 14 is a schematicshowing elements common to both versions, in top and side views(labeled). The sample is seen at 1231 and is under housing 1203 or 1207as the case may be.

Non-limiting exemplary dimensions include 6 cm length, 2.5 cm width, and1.2 cm height.

In some instances, a plastic platform is provided with several verticalslots to provide distance adjustments, capable of holding the variousoptical elements (LED, lens, mirror, filter, photodetector or CCDsensor) and built using, for example, a 3D printer. In some cases, theplane of the sample and the plane of the photodetector are not parallel,requiring an additional mirror to bend the light, but this is not alimitation and the sample and detection planes can be made parallel inother cases. This optical module could, in some cases, be combined withaspects of the electrical, mechanical, and signal processing modulesdescribed in with regard to the first exemplary embodiment.

Third exemplary embodiment: FIGS. 16-26 show various views of a thirdembodiment of a system, in accordance with an aspect of the invention.This embodiment provides multiplexing capabilities. Several DEPcartridges 1601, 1603, 1605 trap the beads and give a signal when thechip is ready for detection. The microfluidics chip is connected to theDEP cartridges using spring-loaded contacts. The reader is not occupiedduring the DEP trapping. Wireless communications can be established forbase station 1607 to communicate with multiple cartridges 1601, 1603,1605. Each cartridge 1601, 1603, 1605 can include a circuit board withDEP electronics 1609, as seen in FIG. 17, as well as an associatedbattery 1611 and battery electronics 1613 underneath.

In this third exemplary embodiment, the electrical module is integratedwith the chip platform and electrical connector to produce a stand-alonemodule for powering the electrodes. The AC signal generator can becontrolled through a physical ON/OFF switch connected to the unit orusing the capacitance liquid position detection described previously.This module communicates wirelessly with the signal processing unit toindicate when the chip is ready for detection, being attached to thebase station 1607 using a tray mechanism, similar to the folding frameand detection module 118, described in FIG. 4, FIG. 5 and FIG. 7. Thisunit can be used under a conventional microscope or combined with theoptical and signal processing modules described in the first exemplaryembodiment to provide the complete solution, flexible enough to beapplied on these two fluorescence measurements solutions.

In at least some cases, the third exemplary embodiment can employ a highdensity connector prototype. In this aspect, electrical interfacing viaspring-loaded contacts increases the number of electrical contacts,keeping the chip size small, and providing approximately three timesmore contacts for the same footprint, as compared with a card edgeinterface, such as Micro SD. Mechanical compression to a Poly(methylmethacrylate) (PMMA) cover secures the chip and an opening allows liquidloading and fluorescence/colorimetric analysis.

FIG. 18 shows a chip 1616 with a standard Micro SD card-edge connectorwith eight contacts 1615 in an approximately 4 mm×9.4 mm area. FIG. 19shows a chip 1618 with an exemplary high-density card-edge connectorwith twenty-one contacts 1617 in an approximately 4 mm×9.4 mm area. FIG.20 shows a printed circuit board (PCB) 1619 on an aluminum base 1629,pivoting about a first screw 1625 and secured by a second screw 1627 inslot 1633. Note chip-receiving cavity 1631 accessible through acorresponding hole in the PCB, as well as standard connector 1621 andPogo pin array 1623. The hole in the PCB is smaller than the cavity, butbig enough to allow optical analysis. In FIG. 21, screws 1625, 1627 areloosened and PCB 1619 pivots away from base 1629. In FIG. 22, chip 1618is placed in cavity 1631 and transparent cover 1635 is brought proximatethe chip. In FIG. 23, cover 1635 is placed over chip 1618, the PCB ispivoted back, and screws 1625, 1627 are tightened to provide compressiveforce symbolized by arrows 1637. In a non-limiting example, PCB 1619 canbe 2.5 cm×9 cm, the standard connector 1621 can have two rows of sevenpins with 2.54 mm pitch, and the Pogo pin array can have two rows ofseven pins with 1.27 mm pitch.

Referring to FIGS. 24-26, this high density connector can be implementedin several different forms, such as slide, hinge or flexible mechanisms.FIG. 24 shows a sliding hinge mechanism wherein PCB 2419 is analogous toPCB 1619, and is joined to bottom portion 2429 (analogous to 1629) byfour links 2499. Note chip-receiving cavity 2431 in bottom portion 2429,with a corresponding hole in the PCB 2419. An initial closed state isshown at the top. A pivoted-open state is shown in the middle. Chip 2418(with any needed cover, not separately numbered) is placed in the cavityand the assembly is closed, in the bottom view.

FIG. 25 shows a flexible contact approach wherein a flexible top portion2519 is joined to bottom portion 2529 (analogous to 1629) at a far edge2599. Note chip-receiving cavity 2531 in bottom portion 2529. An initialstate is shown at the top with the top portion being lifted. An openstate is shown in the middle with chip 2518 (with any needed cover, notseparately numbered) placed in the cavity. The assembly is closed, inthe bottom view.

FIG. 26 shows a hinge lock mechanism wherein a top portion 2619 isjoined to bottom portion 2629 (analogous to 1629) at a far edge 2699.Note chip-receiving cavity 2631 in bottom portion 2629. An initial stateis shown at the top with the top portion being lifted. An open state isshown in the middle with chip 2618 (with any needed cover, notseparately numbered) placed in the cavity. The assembly is closed, inthe bottom view. Locking detents 2697 in the base can engage detents2695 in the top.

Fourth exemplary embodiment: FIGS. 27-30 show various views of a fourthembodiment of a system, in accordance with an aspect of the invention.This embodiment is similar to the third exemplary embodiments, exceptthat smart phone 2707 is used to control DEP cartridges 2701, 2703,2705; capacitance measurements are used to track fluid flow inside themicrochannels, and audio/visual feedback is provided both on the deviceand on the mobile phone, as well as chip presence detection. FIG. 28shows an exploded view of an exemplary cartridge. Note microfluidic chip2801, main board 2803, microcontroller 2805, LI-polymer battery 2807,battery charger and 5V regulator 2809, Bluetooth module 2811, on/offswitch 2813, piezoelectric buzzer 2815, and organic light-emitting diode(OLED) display 2817. FIG. 29 shows a front side of main board 2803, withswitch 2813, buzzer 2815 for sound notification, and DEP circuit 2819.FIG. 30 shows a back side of board 2803, with microcontroller 2805(e.g., Arduino-compatible), Bluetooth module 2811, DC/DC converter 2823(e.g. 5V input with +/−12 V output), 3.3 V regulator 2827, and 3.3 V/5 Vlevel shifter converters 2825.

In the fourth exemplary embodiment a two way wireless communicationchannel exists between the electrical and chip platform module poweringthe electrodes and the signal processing and communications module,which can be in the form of a mobile device 2707. The AC signalgenerator ON/OFF switch can be remotely controlled from the mobiledevice automatically or through a user interface. This setup can be usedunder a conventional microscope or can be combined with an opticalmodule as described with respect to the third exemplary embodiment.

In the fourth exemplary embodiment, regarding liquid position detection,detection of chip presence and liquid position can be based on impedance(in this example, capacitance sensing). Typical common failures presentin microfluidic devices (leakage, clogging, etc.) can be detected basedon the time between each impedance measurement from specific checkpoints. FIG. 31 shows a top view of a microfluidic chip 3101 includingcontacts 3103, capillary pump 3105, impedance detection electrodes 3107,DEP electrodes 3109, channel 3111, and liquid loading pad 3113. Thelarge encircled numbers one through five key the top view of themicrofluidics chip to corresponding portions of the flow chart. The flowchart begins at 3115. In decision block 3117, determine whether the chipis inserted (i.e., is there contact with contacts 3103). If NO, continueto check and wait until a chip is detected. If YES, proceed to decisionblock 3119 and determine whether there has been a change in impedance.If NO, continue to check. If YES, liquid has been loaded at loading pad3113; start the timer in step 3121 to allow the liquid to fill up themicrochannel 3111. In decision block 3123, again determine whether therehas been a change in impedance (i.e.: microchannel 3111 is alreadyfilled up with the sample). If NO, proceed to decision block 3125 anddetermine whether the timer is less than a maximum predefined value. Ifnot, there has been an error, as at 3127, such as clogging, bubbleformation, and/or high flow resistance, as at 3129.

If decision block 3125 yields a YES, continue to check for impedancechanges until timer expiration.

If decision block 3123 yields a YES, continue to decision block 3131 anddetermine whether the timer is greater than a minimum predefined value.If not, there has been an error, as at 3133, such as a liquid leakand/or low flow resistance, as at 3135.

If decision block 3131 yields a YES, there is normal liquid flow—proceedto step 3137, turn on the DEP and start the readout. Continue todecision block 3139. In decision block 3139, again determine whetherthere has been a change in impedance. If NO, proceed to decision block3141 and determine whether the timer is less than a maximum predefinedvalue. If not, there has been an error, as at 3143, such as clogging,bubble formation, and/or high flow resistance, as at 3145.

If decision block 3141 yields a YES, continue to check for impedancechanges and/or timer expiration.

If decision block 3139 yields a YES, continue to decision block 3147 anddetermine whether the timer is greater than a minimum predefined value.If not, there has been an error, as at 3149, such as a liquid leakand/or low flow resistance, as at 3151. If YES, proceed to step 3153 anddisplay (and/or output) the results.

FIG. 32 shows an alternative view of microfluidics chip 3101 includingcontacts 3103, DEP electrodes 3109, and liquid loading pad 3113. Thearrow 3155 shows flow as a function of time. Please note that in FIG.31, there are two pairs of electrodes dedicated to flow detection, whilein FIG. 32 there is only a pair of electrodes dedicated to DEPexcitation.

FIG. 33 shows a circuit diagram associated with testing aspects of thefourth embodiment of the system. CT is the capacitance under test(unknown), which is, in this case, the capacitance between theelectrodes deposited in the microchannels (impedance detectionelectrodes 3107 in FIG. 31). CT will change when the channel is filledup with the liquid sample, compared to when it was filled with air. C1is a stray capacitance (say, about 30 pF, typically). Voltage V1 isapplied at A2. For example, A2 may have its voltage increase from 0V to5V in about 5 ns. The voltage on A0 can then be measured after about 30ns. CT is calculated as the voltage at A0 times C1, divided by thedifference between the voltage at A2 and the voltage at A0. This is sobecause for capacitors in series, each holds the same charge Q; thus, CTtimes the voltage drop across it (V_(A2)-V_(A0)) equals C1 times thevoltage drop across it (V_(A0)). The A0 node can be connected to anysuitable microcontroller port that allows analog measurements.

FIG. 34 shows a graph of capacitance versus time from the testingaspects of FIGS. 32 and 33, in accordance with an aspect of theinvention. In particular, FIG. 34 shows a typical variation of themeasurement carried out by the impedance detection electrodes 3107 (CT)in time, after the sample is put in loading pad 3113.

The position of the fluid within the channel can be determined usingdedicated electrodes positions at various checkpoints along themicrochannel. These electrodes are connected to a microcontroller (e.g.,Arduino) capable of measuring the capacitance between the contacts,which changes noticeably when the electrodes are covered by the liquid.This capacitance measurement is fed back wirelessly to the signalprocessing unit to determine the position of the fluid and control theAC signal generator ON/OFF switch remotely and accordingly, which can bedone automatically following an algorithm without any intervention fromthe user.

FIG. 35 shows a circuit diagram of a DEP cartridge of the fourthembodiment of the system. The following tables show the ports andsignals, and the voltage levels:

TABLE I Port Signal Bluetooth Serial (receive (RX), transmit (TX)) OLEDDisplay I²C (inter integrated circuit) (Serial Data Line (SDA) andSerial Clock Line (SCL)) DEP Control Pulse width modulation (PWM)amplitude control and digital on/off Buzzer Pulse width modulation (PWM)Soft reset Digital (active-low)

TABLE II Voltage Level Location +3.3 V Bluetooth +3.7 V Li—Po battery  +5 V DEP oscillator, Arduino, OLED +/−15 V  DEP circuit

The output of oscillator 3501 is buffered in buffer 3503 and then fed tothe input of op amp 3505 through capacitor 3507 and resistor 3509. Theop amp is in negative feedback configuration, in which the gain iscontrolled with the ratio between resistors 3511 and 3509. The positiveinput of op amp 3505 is grounded. The output of op amp 3505 is alsoprovided to switch 3513. When the DEP signal from the microcontroller2805 is ON, switch 3513 connects the output of op amp 3505 to buffer3515, which then provides the buffered output to the DEP contact ofcartridge 3101. When the DEP signal from the microcontroller 2805 isOFF, switch 3513 grounds the input of buffer 3515. Op-amp 3599 isworking as a unity gain buffer input for the oscillator 3501. The PWMsignal will provide a variable voltage for the VCC oscillator input. Inparticular, one or more embodiments generate a DC voltage using PWM anda low pass filter (Resistor and Capacitor), then apply this voltage tothe VCC of the oscillator. Because the oscillator generates a squarewave varying from 0V to VCC, change the amplitude of the DEP signal bychanging the VCC. Op-amp 3505 amplifies the signal using 3509 and 3511.Cap 3507 removes the DC offset, so that a square pulse is obtained, withan average value at 0V. Other elements in FIG. 35 are discussedelsewhere herein.

Fifth exemplary embodiment: In a fifth exemplary embodiment, depicted inFIGS. 36-39, the entire system (mechanical, electronic and opticalmodules) is compactly integrated into a single attachment 3604 for amobile device 3602. The image sensor and parts of the signal processingand communications module can exploit capabilities of current mobiledevices, thereby reducing cost. For example, some modern mobile deviceshave dual or quad core central processing units (CPUs) with ˜2 GHz andWiFi, Bluetooth, NFC, 3G, and/or LTE capability. This can lead toreduced cost and enhanced processing and user interface capabilities aswell as providing an interface to cloud and data analytics. For example,a single compact highly integrated attachment to a mobile device iscustomized and built using low cost materials and integratingelectrical, optical and mechanical modules only. The camera, computingand communication capability of the mobile device can be exploited asparts of the optical and signal processing and communication modules,respectively. As seen in FIG. 37, attachment 3604 includes a lens andmirror arrangement 3606 as described with regard to, e.g., FIGS. 12-15,which directs light to and from the chip 3101 and is located adjacentthe camera lens (not separately numbered; see discussion of camera 8039below) of the mobile device 3602. Element 3608 can includeelectromechanical and electro-optical functionality not provided bydevice 3602. FIG. 39 shows an exemplary screen shot including timeremaining, buttons for DEP, readout, and on/off, and a voltage versustime graph.

This fifth exemplary embodiment relies on the ubiquity of smartphones,which could further employ an already existing computationalinfrastructure, such as cloud computer service, to allow dataaggregation and analysis over several analyses, to obtain, for example,geographical disease distribution and outbreaks patterns. See thediscussion of an exemplary “smart” device (FIG. 40 and accompanyingtext) and exemplary cloud environment (FIGS. 41-41 and accompanyingtext) that follow.

Exemplary Mobile Device

FIG. 40 is a block diagram of an exemplary tablet computing device,netbook, laptop, mobile electronic device, or smart phone 8000 or thelike. Unit 8000 includes a suitable processor; e.g., a microprocessor8002. A cellular transceiver module 8004 coupled to processor 8002includes an antenna and appropriate circuitry to send and receivecellular telephone signals, e.g., 3G or 4G. In some cases, a Wi-Fitransceiver module 8006 coupled to processor 8002 includes an antennaand appropriate circuitry to allow unit 8000 to connect to the Internetvia a wireless network access point or hotspot. The skilled artisan willappreciate that “Wi-Fi” is a trademark of the Wi-Fi Alliance and thebrand name for products using the IEEE 802.11 family of standards. Insome cases, a Bluetooth transceiver module 8029 coupled to processor8002 includes an antenna and appropriate circuitry to allow unit 8000 toconnect to other devices via the Bluetooth wireless technology standard.In some cases, an NFC transceiver module 8031 coupled to processor 8002includes an antenna and appropriate circuitry to allow unit 8000 toestablish radio communication via near-field communications.

Operating system (OS) 8027 orchestrates the operation of unit 8000.

Touch screen 8010 coupled to processor 8002 is also generally indicativeof a variety of input/output (I/O) devices such as a keypad, anothertype of display, a mouse or other pointing device, and so on, all ofwhich may or may not be present in one or more embodiments. Audio module8018 coupled to processor 8002 includes, for example, an audiocoder/decoder (codec), speaker, headphone jack, microphone, and so on.Power management system 8016 can include a battery charger, an interfaceto a battery, and so on. Memory 8012 is coupled to processor 8002.Memory 8012 can include, for example, volatile memory such as RAM, andnon-volatile memory such as ROM, flash, or any tangiblecomputer-readable recordable storage medium which stores information ina non-transitory manner. Processor 8002 will typically also have on-chipmemory.

A digital camera 8039 is coupled to processor 8002.

A GPS receiver module 8099 coupled to processor 8002 includes an antennaand appropriate circuitry to allow device 8000 to calculate its positionby precisely timing the signals sent by GPS satellites high above theEarth. Corresponding software resides in memory 8012.

Note that elements in FIG. 40 are shown connected directly to processor8002; however, one or more bus structures can be employed in one or moreembodiments. Furthermore, elements shown as implemented in software maybe implemented at least in part in hardware for speed, if desired.

Browser program 8097 in memory 8012 deciphers hypertext markup language(html) served out by a server (e.g. cloud computing node discussedelsewhere) for display on screen 8010 or the like.

Application 8045 in memory 8012 can be provided to control theembodiment of FIGS. 36-39.

Every instance need not necessarily have every feature depicted in FIG.40.

Exemplary Cloud Computing Environment

It is understood in advance that although this disclosure includes adetailed description on cloud computing, implementation of the teachingsrecited herein are not limited to a cloud computing environment. Rather,embodiments of the present invention are capable of being implemented inconjunction with any other type of computing environment now known orlater developed.

Cloud computing is a model of service delivery for enabling convenient,on-demand network access to a shared pool of configurable computingresources (e.g. networks, network bandwidth, servers, processing,memory, storage, applications, virtual machines, and services) that canbe rapidly provisioned and released with minimal management effort orinteraction with a provider of the service. This cloud model may includeat least five characteristics, at least three service models, and atleast four deployment models.

Characteristics are as follows:

On-demand self-service: a cloud consumer can unilaterally provisioncomputing capabilities, such as server time and network storage, asneeded automatically without requiring human interaction with theservice's provider.

Broad network access: capabilities are available over a network andaccessed through standard mechanisms that promote use by heterogeneousthin or thick client platforms (e.g., mobile phones, laptops, and PDAs).

Resource pooling: the provider's computing resources are pooled to servemultiple consumers using a multi-tenant model, with different physicaland virtual resources dynamically assigned and reassigned according todemand. There is a sense of location independence in that the consumergenerally has no control or knowledge over the exact location of theprovided resources but may be able to specify location at a higher levelof abstraction (e.g., country, state, or datacenter).

Rapid elasticity: capabilities can be rapidly and elasticallyprovisioned, in some cases automatically, to quickly scale out andrapidly released to quickly scale in. To the consumer, the capabilitiesavailable for provisioning often appear to be unlimited and can bepurchased in any quantity at any time.

Measured service: cloud systems automatically control and optimizeresource use by leveraging a metering capability at some level ofabstraction appropriate to the type of service (e.g., storage,processing, bandwidth, and active user accounts). Resource usage can bemonitored, controlled, and reported providing transparency for both theprovider and consumer of the utilized service.

Service Models are as follows:

Software as a Service (SaaS): the capability provided to the consumer isto use the provider's applications running on a cloud infrastructure.The applications are accessible from various client devices through athin client interface such as a web browser (e.g., web-based email). Theconsumer does not manage or control the underlying cloud infrastructureincluding network, servers, operating systems, storage, or evenindividual application capabilities, with the possible exception oflimited user-specific application configuration settings.

Platform as a Service (PaaS): the capability provided to the consumer isto deploy onto the cloud infrastructure consumer-created or acquiredapplications created using programming languages and tools supported bythe provider. The consumer does not manage or control the underlyingcloud infrastructure including networks, servers, operating systems, orstorage, but has control over the deployed applications and possiblyapplication hosting environment configurations.

Infrastructure as a Service (IaaS): the capability provided to theconsumer is to provision processing, storage, networks, and otherfundamental computing resources where the consumer is able to deploy andrun arbitrary software, which can include operating systems andapplications. The consumer does not manage or control the underlyingcloud infrastructure but has control over operating systems, storage,deployed applications, and possibly limited control of select networkingcomponents (e.g., host firewalls).

Deployment Models are as follows:

Private cloud: the cloud infrastructure is operated solely for anorganization. It may be managed by the organization or a third party andmay exist on-premises or off-premises.

Community cloud: the cloud infrastructure is shared by severalorganizations and supports a specific community that has shared concerns(e.g., mission, security requirements, policy, and complianceconsiderations). It may be managed by the organizations or a third partyand may exist on-premises or off-premises.

Public cloud: the cloud infrastructure is made available to the generalpublic or a large industry group and is owned by an organization sellingcloud services.

Hybrid cloud: the cloud infrastructure is a composition of two or moreclouds (private, community, or public) that remain unique entities butare bound together by standardized or proprietary technology thatenables data and application portability (e.g., cloud bursting for loadbalancing between clouds).

A cloud computing environment is service oriented with a focus onstatelessness, low coupling, modularity, and semantic interoperability.At the heart of cloud computing is an infrastructure comprising anetwork of interconnected nodes.

Referring now to FIG. 41, a schematic of an example of a cloud computingnode is shown. Cloud computing node 10 is only one example of a suitablecloud computing node and is not intended to suggest any limitation as tothe scope of use or functionality of embodiments of the inventiondescribed herein. Regardless, cloud computing node 10 is capable ofbeing implemented and/or performing any of the functionality set forthhereinabove.

In cloud computing node 10 there is a computer system/server 12, whichis operational with numerous other general purpose or special purposecomputing system environments or configurations. Examples of well-knowncomputing systems, environments, and/or configurations that may besuitable for use with computer system/server 12 include, but are notlimited to, personal computer systems, server computer systems, thinclients, thick clients, handheld or laptop devices, multiprocessorsystems, microprocessor-based systems, set top boxes, programmableconsumer electronics, network PCs, minicomputer systems, mainframecomputer systems, and distributed cloud computing environments thatinclude any of the above systems or devices, and the like.

Computer system/server 12 may be described in the general context ofcomputer system executable instructions, such as program modules, beingexecuted by a computer system. Generally, program modules may includeroutines, programs, objects, components, logic, data structures, and soon that perform particular tasks or implement particular abstract datatypes. Computer system/server 12 may be practiced in distributed cloudcomputing environments where tasks are performed by remote processingdevices that are linked through a communications network. In adistributed cloud computing environment, program modules may be locatedin both local and remote computer system storage media including memorystorage devices.

As shown in FIG. 1, computer system/server 12 in cloud computing node 10is shown in the form of a general-purpose computing device. Thecomponents of computer system/server 12 may include, but are not limitedto, one or more processors or processing units 16, a system memory 28,and a bus 18 that couples various system components including systemmemory 28 to processor 16.

Bus 18 represents one or more of any of several types of bus structures,including a memory bus or memory controller, a peripheral bus, anaccelerated graphics port, and a processor or local bus using any of avariety of bus architectures. By way of example, and not limitation,such architectures include Industry Standard Architecture (ISA) bus,Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, VideoElectronics Standards Association (VESA) local bus, and PeripheralComponent Interconnect (PCI) bus.

Computer system/server 12 typically includes a variety of computersystem readable media. Such media may be any available media that isaccessible by computer system/server 12, and it includes both volatileand non-volatile media, removable and non-removable media.

System memory 28 can include computer system readable media in the formof volatile memory, such as random access memory (RAM) 30 and/or cachememory 32. Computer system/server 12 may further include otherremovable/non-removable, volatile/non-volatile computer system storagemedia. By way of example only, storage system 34 can be provided forreading from and writing to a non-removable, non-volatile magnetic media(not shown and typically called a “hard drive”). Although not shown, amagnetic disk drive for reading from and writing to a removable,non-volatile magnetic disk (e.g., a “floppy disk”), and an optical diskdrive for reading from or writing to a removable, non-volatile opticaldisk such as a CD-ROM, DVD-ROM or other optical media can be provided.In such instances, each can be connected to bus 18 by one or more datamedia interfaces. As will be further depicted and described below,memory 28 may include at least one program product having a set (e.g.,at least one) of program modules that are configured to carry out thefunctions of embodiments of the invention.

Program/utility 40, having a set (at least one) of program modules 42,may be stored in memory 28 by way of example, and not limitation, aswell as an operating system, one or more application programs, otherprogram modules, and program data. Each of the operating system, one ormore application programs, other program modules, and program data orsome combination thereof, may include an implementation of a networkingenvironment. Program modules 42 generally carry out the functions and/ormethodologies of embodiments of the invention as described herein.

Computer system/server 12 may also communicate with one or more externaldevices 14 such as a keyboard, a pointing device, a display 24, etc.;one or more devices that enable a user to interact with computersystem/server 12; and/or any devices (e.g., network card, modem, etc.)that enable computer system/server 12 to communicate with one or moreother computing devices. Such communication can occur via Input/Output(I/O) interfaces 22. Still yet, computer system/server 12 cancommunicate with one or more networks such as a local area network(LAN), a general wide area network (WAN), and/or a public network (e.g.,the Internet) via network adapter 20. As depicted, network adapter 20communicates with the other components of computer system/server 12 viabus 18. It should be understood that although not shown, other hardwareand/or software components could be used in conjunction with computersystem/server 12. Examples, include, but are not limited to: microcode,device drivers, redundant processing units, and external disk drivearrays, RAID systems, tape drives, and data archival storage systems,etc.

Referring now to FIG. 42, illustrative cloud computing environment 50 isdepicted. As shown, cloud computing environment 50 comprises one or morecloud computing nodes 10 with which local computing devices used bycloud consumers, such as, for example, personal digital assistant (PDA)or cellular telephone 54A, desktop computer 54B, laptop computer 54C,and/or automobile computer system 54N may communicate. Nodes 10 maycommunicate with one another. They may be grouped (not shown) physicallyor virtually, in one or more networks, such as Private, Community,Public, or Hybrid clouds as described hereinabove, or a combinationthereof. This allows cloud computing environment 50 to offerinfrastructure, platforms and/or software as services for which a cloudconsumer does not need to maintain resources on a local computingdevice. It is understood that the types of computing devices 54A-N shownin FIG. 42 are intended to be illustrative only and that computing nodes10 and cloud computing environment 50 can communicate with any type ofcomputerized device over any type of network and/or network addressableconnection (e.g., using a web browser).

Referring now to FIG. 43, a set of functional abstraction layersprovided by cloud computing environment 50 (FIG. 42) is shown. It shouldbe understood in advance that the components, layers, and functionsshown in FIG. 43 are intended to be illustrative only and embodiments ofthe invention are not limited thereto. As depicted, the following layersand corresponding functions are provided:

Hardware and software layer 60 includes hardware and softwarecomponents. Examples of hardware components include mainframes, in oneexample IBM® zSeries® systems; RISC (Reduced Instruction Set Computer)architecture based servers, in one example IBM pSeries® systems; IBMxSeries® systems; IBM BladeCenter® systems; storage devices; networksand networking components. Examples of software components includenetwork application server software, in one example IBM Web Sphere®application server software; and database software, in one example IBMDB2® database software. (IBM, zSeries, pSeries, xSeries, BladeCenter,WebSphere, and DB2 are trademarks of International Business MachinesCorporation registered in many jurisdictions worldwide).

Virtualization layer 62 provides an abstraction layer from which thefollowing examples of virtual entities may be provided: virtual servers;virtual storage; virtual networks, including virtual private networks;virtual applications and operating systems; and virtual clients.

In one example, management layer 64 may provide the functions describedbelow. Resource provisioning provides dynamic procurement of computingresources and other resources that are utilized to perform tasks withinthe cloud computing environment. Metering and Pricing provide costtracking as resources are utilized within the cloud computingenvironment, and billing or invoicing for consumption of theseresources. In one example, these resources may comprise applicationsoftware licenses. Security provides identity verification for cloudconsumers and tasks, as well as protection for data and other resources.User portal provides access to the cloud computing environment forconsumers and system administrators. Service level management providescloud computing resource allocation and management such that requiredservice levels are met. Service Level Agreement (SLA) planning andfulfillment provides pre-arrangement for, and procurement of, cloudcomputing resources for which a future requirement is anticipated inaccordance with an SLA.

Workloads layer 66 provides examples of functionality for which thecloud computing environment may be utilized. Examples of workloads andfunctions which may be provided from this layer include: mapping andnavigation; software development and lifecycle management; virtualclassroom education delivery; data analytics processing; transactionprocessing; and mobile desktop, as well as data aggregation and analysisover several analyses, to obtain, for example, geographical diseasedistribution and outbreaks patterns, as discussed above.

Recapitulation

Given the discussion thus far, it will be appreciated that, in generalterms, an exemplary assembly is provided for interfacing with amicrofluidic chip 238, 1616, 1618 having at least one microscopicchannel configured to receive a liquid sample for analysis, at least oneelectrode embedded in the channel (e.g., at 969 and 3109), and at leastone chip contact 1615, 1617 coupled to the at least one embeddedelectrode (for example, for dielectrophoresis, electro-osmosis,electro-wetting and/or liquid impedance detection). The assemblyincludes a chip carrier, which in turn includes a base (not separatelynumbered in FIG. 4) and a cover 240, cooperatively defining, with thebase, a cavity 236 configured and dimensioned to receive themicrofluidic chip 238. The cover is attachable to the base (e.g.,already attached such as by hinge 252 or separate but capable of beingattached by snapping or other suitable technique), to secure themicrofluidic chip in the cavity of the base. The cover has an aperture244 to permit the microscopic channel of the microfluidic chip toreceive the sample for analysis and/or to permit passage of excitationand emission radiation. Also provided is at least one chip carriercontact to engage the at least one chip contact.

The assembly further includes an electronics module 110, which in turnincludes at least one electronics module contact that engages the atleast one chip carrier contact (e.g. flex cable 248); and a signalgenerator 112, coupled to the at least one electronics module contact,which applies (e.g. time multiplexing) at least one electrokineticsignal to the at least one embedded electrodes.

Please note that in many cases there will be a plurality of electrodesand a corresponding plurality of all the contacts. The signal generatorwill then selectively apply (e.g. time multiplexing) a plurality ofelectrokinetic signals to the plurality of embedded electrodes.

In a non-limiting example, the embedded electrodes are dielectrophoresiselectrodes, and the electrokinetic signals are dielectrophoresissignals.

The assembly even further includes an optical module 118, which in turnincludes an excitation radiation source 120, which causes excitationradiation to impinge on the sample through the aperture; and an emissionradiation detector 124 which detects radiation emitted from the samplethrough the aperture. The assembly still further includes a mechanicalmodule 102 including a chip-carrier receiving structure (see, e.g.,FIGS. 11-1107) relatable with respect to the optical module for focusand at least one degree of translational freedom. The mechanical moduleis electrically coupled to the electronics module. The focus and the atleast one degree of translational freedom are controlled by theelectronics module via the electrical coupling.

At least some embodiments further include a signal processing module126, electrically coupled to the emission radiation detector 124, whichprocesses a signal indicative of the radiation emitted from the samplethrough the aperture for communication to an operator. Communicationscan be wired and/or wireless. The signal processing module can beintegrated with the electronics module or stand-alone. In at least somecases, the cavity 236 configured and dimensioned to receive themicrofluidic chip 238 is formed in the base of the chip carrier; and theplurality of chip carrier contacts 234 are formed on the cover of thechip carrier.

In at least some cases, the cover of the chip carrier is secured to thebase of the chip carrier with at least one hinge 252 and a securemechanism 242. The cover of the chip carrier has a side which faces thebase of the chip carrier, and which is provided, in some instances, witha hydrophobic cushion layer 246 to avoid contamination.

As seen, for example, in FIG. 11, some embodiments further include ahousing 1101. The electronics module and the optical module can belocated in the housing, and wherein the housing is formed with a regionto receive the chip carrier 1107.

As seen for example in FIG. 7, in some instances, the electronics moduleis located in the chip carrier and the optical module is located in thehousing, and the housing is formed with a region to receive the chipcarrier.

As seen for example in FIG. 9, in some instances, the electronics moduleis located in the base of the chip carrier and the optical module islocated in the cover of the chip carrier.

Some claims recite the chip as a workpiece in the preamble but do notexplicitly claim it, while other claims additionally claim themicrofluidic chip, which can be located in the cavity configured anddimensioned to receive the microfluidic chip.

In at least some cases, the at least one microscopic channel is sized tocause flow of the liquid sample by capillary action (e.g., capillarypump 3105).

In some cases, the at least one microscopic channel is formed with aloading pad region (seen under dropper at 250), and the at least onemicroscopic channel, the loading pad region, and the plurality ofdielectrophoresis electrodes are collocated on a first side of the chipwhich faces the optical module 118. The plurality of chip contacts canalso be located on the first side of the chip, and in some instances,are formed as a high density connector array. Such an array could bearranged, by way of example and not limitation, in at least one row ofcontacts in an area less than 100 square millimeters; in one specificnon-limiting example, three rows of seven contacts in an area 4millimeters by 9.4 millimeters, as seen in FIG. 19.

For the avoidance of doubt, the values in the previous paragraph areexemplary and non-limiting. Other embodiments do not necessarily have anupper area limit for the connectors, since the chip area is also notlimited in one or more embodiments, except to keep costs reasonable.Internal arrangement of the microfluidics channels and the capillarypump could also be modified in some instances to free up space.

In some cases, the optical module further includes a mirror and lensassembly 1203 moveable with respect to the excitation radiation source,and the chip-carrier receiving structure is relatable with respect tothe optical module for the focus and the at least one degree oftranslational freedom by keeping the chip-carrier receiving structurestill and moving the mirror and lens assembly.

In another aspect, referring to FIG. 31, an exemplary method is providedfor carrying out a test on a microfluidic chip having at least onemicroscopic channel 3111 configured to receive a liquid sample foranalysis (e.g., on a loading pad), at least one analytic electrode (see,e.g., exemplary pair of electrodes 3109, in an interdigitated layout;multiple electrode pairs could be used for DEP purposes in otherembodiments) embedded in the channel, a plurality ofliquid-presence-sensing electrodes embedded in the channel, and aplurality of chip contacts 3103 coupled to the at least one analyticelectrode and the plurality of liquid-presence-sensing electrodes. Themethod includes step 3119, detecting loading of the liquid sample, on afirst such microfluidic chip, based on an impedance change at one of theliquid-presence-sensing electrodes. A further step 3121 includes,responsive to detecting the sample loading, on the first suchmicrofluidic chip, starting a timer. An even further step 3137 includes,responsive to an impedance change at at least another one of theliquid-presence-sensing electrodes (as at 3123), when the timer hasadvanced past a first threshold but has not advanced past a secondthreshold (as at 3125, 3131), commencing application of electrokineticsignals to the at least one embedded analytic electrode.

Please note that the at least one embedded analytic electrode could beone of the liquid-presence-sensing electrodes or could be separate anddistinct from the liquid-presence-sensing electrodes. Dedicatedelectrode pairs could be used for liquid position detection or the samepair of electrodes could be used for DEP (or other analysis) and liquidposition detection. Thus, the at least one embedded analytic electrodecould, but need not, be a dielectrophoresis electrode, and theelectrokinetic signals could, but need not, be dielectrophoresissignals.

Referring to the encircled “5” in FIG. 31 as well as the capillary pump3105 and decision block 3139, note that there is a pair of electrodes3199 to detect capacity variation inside the capillary pump. The reasonto continue the liquid monitoring (check for impedance change at 3139)is to ensure that the liquid continues to flow. To simplify, liquidpresence measurements are undertaken at the beginning (at the loadingpad 3113 see encircled “2” and decision block 3119), in the beginning(see encircled “3” and decision block 3119, electrodes 3107) and in theend of the capillary pump (see encircled “5” and decision block 3139,electrodes 3199).

In some cases, the method includes repeating the detecting and startingsteps for another liquid sample on another chip when chips are notreusable, and, responsive to an impedance change at the at least anotherone of the embedded electrodes, when the timer has not advanced past thefirst threshold, outputting an error signal to indicate at least one ofpotential leakage and low flow resistance (NO branch of 3131 to 3133).

In some cases, the method includes repeating the detecting and startingsteps for another liquid sample on another chip when chips are notreusable, and, responsive to no impedance change at the at least anotherone of the embedded electrodes prior to the timer advancing past thesecond threshold, outputting an error signal to indicate at least one ofpotential clogging, bubble formation, and high flow resistance (NObranches of 3123, 3125 to 3127).

Aspects of one or more embodiments of the invention, or elementsthereof, can be implemented in the form of an apparatus including amemory and at least one processor that is coupled to the memory andoperative to perform exemplary method steps (e.g., smart phone, cloudserver).

One or more embodiments can make use of software running on a generalpurpose computer or workstation. With reference to FIG. 41, such animplementation might employ, for example, a processor 16, a memory 28,and an input/output interface 22 to a display 24 and external device(s)14 such as a keyboard, a pointing device, or the like. The term“processor” as used herein is intended to include any processing device,such as, for example, one that includes a CPU (central processing unit)and/or other forms of processing circuitry. Further, the term“processor” may refer to more than one individual processor. The term“memory” is intended to include memory associated with a processor orCPU, such as, for example, RAM (random access memory) 30, ROM (read onlymemory), a fixed memory device (for example, hard drive 34), a removablememory device (for example, diskette), a flash memory and the like. Inaddition, the phrase “input/output interface” as used herein, isintended to contemplate an interface to, for example, one or moremechanisms for inputting data to the processing unit (for example,mouse), and one or more mechanisms for providing results associated withthe processing unit (for example, printer). The processor 16, memory 28,and input/output interface 22 can be interconnected, for example, viabus 18 as part of a data processing unit 12. Suitable interconnections,for example via bus 18, can also be provided to a network interface 20,such as a network card, which can be provided to interface with acomputer network, and to a media interface, such as a diskette or CD-ROMdrive, which can be provided to interface with suitable media.

Accordingly, computer software including instructions or code forperforming the methodologies of the invention, as described herein, maybe stored in one or more of the associated memory devices (for example,ROM, fixed or removable memory) and, when ready to be utilized, loadedin part or in whole (for example, into RAM) and implemented by a CPU.Such software could include, but is not limited to, firmware, residentsoftware, microcode, and the like.

A data processing system suitable for storing and/or executing programcode will include at least one processor 16 coupled directly orindirectly to memory elements 28 through a system bus 18. The memoryelements can include local memory employed during actual implementationof the program code, bulk storage, and cache memories 32 which providetemporary storage of at least some program code in order to reduce thenumber of times code must be retrieved from bulk storage duringimplementation.

Input/output or I/O devices (including but not limited to keyboards,displays, pointing devices, and the like) can be coupled to the systemeither directly or through intervening I/O controllers.

Network adapters 20 may also be coupled to the system to enable the dataprocessing system to become coupled to other data processing systems orremote printers or storage devices through intervening private or publicnetworks. Modems, cable modem and Ethernet cards are just a few of thecurrently available types of network adapters.

As used herein, including the claims, a “server” includes a physicaldata processing system (for example, system 12 as shown in FIG. 41)running a server program. It will be understood that such a physicalserver may or may not include a display and keyboard.

One or more embodiments can be at least partially implemented in thecontext of a cloud or virtual machine environment, although this isexemplary and non-limiting.

Reference is made back to FIGS. 41-43 and accompanying text.

It should be noted that any of the methods described herein can includean additional step of providing a system comprising distinct softwaremodules embodied on a computer readable storage medium. The method stepscan then be carried out using the distinct software modules and/orsub-modules of the system, executing on one or more hardware processorssuch as 16. Further, a computer program product can include acomputer-readable storage medium with code adapted to be implemented tocarry out one or more method steps described herein, including theprovision of the system with the distinct software modules.

One example of user interface is hypertext markup language (HTML) codeserved out by a server or the like, to a browser of a computing deviceof a user (e.g., “smart” phone). The HTML is parsed by the browser onthe user's computing device to create a graphical user interface (GUI).

Exemplary System and Article of Manufacture Details

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdisclosed herein.

What is claimed is:
 1. A method for carrying out a test on amicrofluidic chip having at least one microscopic channel configured toreceive a liquid sample for analysis, at least one analytic electrodeembedded in the channel, a plurality of liquid-presence-sensingelectrodes embedded in the channel, and a plurality of chip contactscoupled to the at least one analytic electrode and the plurality ofliquid-presence-sensing electrodes, said method comprising: detectingloading of said liquid sample, on a first such microfluidic chip, basedon an impedance change at a first one of said liquid-presence-sensingelectrodes; responsive to detecting said loading, on said first suchmicrofluidic chip, starting a timer; and responsive to an impedancechange at at least another one of said embedded liquid-presence-sensingelectrodes, on said first such microfluidic chip, when said timer hasadvanced past a first threshold but has not advanced past a secondthreshold, commencing application of electrokinetic signals to said atleast one embedded analytic electrode.
 2. The method of claim 1,wherein, in said detecting and commencing application steps, said atleast one embedded analytic electrode comprises one of saidliquid-presence-sensing electrodes.
 3. The method of claim 1, wherein,in said detecting and commencing application steps, said at least oneembedded analytic electrode is separate and distinct from saidliquid-presence-sensing electrodes.
 4. The method of claim 1, whereinthe at least one embedded analytic electrode comprises adielectrophoresis electrode, and wherein, in said commencing applicationstep, said electrokinetic signals comprise dielectrophoresis signals. 5.The method of claim 4, further comprising: repeating said detecting andstarting steps for another liquid sample with a second such microfluidicchip; and responsive to an impedance change at said at least another oneof said embedded liquid-presence-sensing electrodes on said second suchmicrofluidic chip, when said timer has not advanced past said firstthreshold, outputting an error signal to indicate at least one ofpotential leakage and low flow resistance.
 6. The method of claim 4,further comprising: repeating said detecting and starting steps foranother liquid sample with a second such microfluidic chip; andresponsive to no impedance change at said at least another one of saidembedded liquid-presence-sensing electrodes prior to said timeradvancing past said second threshold, outputting an error signal toindicate at least one of potential clogging, bubble formation, and highflow resistance.